Machine-switching telephone-exchange system.



A. E. LUNDELL.

MACHINE SWITCHING TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED APR. 26.I916.

Patented Jan. 1, 1918.

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UNITED STATES PATENT orrron,

ALBEN' E. LUNDELL, OF NEW YORK, N. .Y., ASSIGNOB, -T0WESTERN.ELECTRIGCOMB-ANY, INCORPORATED, OF NEW YORK, N. Y., ACORPORATION -OF NEW YORK.

MACHINE-SWITCHING TELEPHONE-EXCHANGE SYSTEM.

Specification of Letters Patent.

PatentedJan. 1,1918.

Application filed April 26, 1 916. Serial No. 93,639.

To all whom it may concern:

Be it known that I, ALBEN E. LUNDELL, a citizen of the United States,residingat New York, in the county of Bronx and State of New York, haveinvented-certain new and useful Improvements in Machine- SwitchingTelephoneExchange Systems,of which the following is a full, clear,concise,

"and exact description.

advanced to the next idle finder after the initiation of a call.

The object of this invention is tore'duce this'interval, and the noveltyconsists in a circuit arrangement wherein, in a finder having a primaryand secondary movement. a circuit arrangement is provided for extendingthe starter wire to the next idle finder upon the termination of theprimary movement of such finder in seeking a calling line, instead ofupon the termination of the secondary movement of such finder.

Referring to the drawing, which shows only so much of a telephoneexchange system as is necessary for a comprehension of the invention.the lines terminate in multiples 12S 129 of a number of automatic finderEach line is also provided in the finders with test multiples 110, andwith the usual line and cut-off relays 100, 102. The finder brushes aredesignated 125, 126, 127 and are adapted to be given a primary movementby a magnet 119 to position the same in operative relation to the groupof multiples containing the calling line and a secondary movement by amagnet 133 to pick out the calling line multiples in the group.

The invention will be more clearly understood by tracing the operationsinvolved in sett ng up a connection.

Upon the removal of the receiver by the subscriber at substation A, linerelay 100 is energized'over the following circuit: free pole ofbatteryleft winding of relay 100,

conductor. 101, left armature and bfiCkCQl'ltact of cut-off relay 102,conductor-103, line conductor '101,"t'elephonic' apparatusat -sub isclosed to energize the escape -magnet 122 station A, line conductor-105,conductor 106, right armature and back contact of relay 102, conductor107, right winding ofrelay .100 to ground. Relay 100, in attracting itsleft armature, closes the following shunt path aboutthe cut-oft relay102- to test multiples 110 of the calling line: free pole of battery,

resistance 108, left armature and front con tact of relay 100,conductors 109 and 135. The closure of this shunt pathabout the cutoffrelay 102 causes a calling conditiontobe placed upon the test multiples110 in the finders in which line A appears. Relay 100, in attracting itsright armature, closes the following circuit for a starting relay 11 1:

free pole of battery, resistance 112, right armatureand front contact ofrelay 100, 'conductor113, relay 114: to ground. The

closure of thiscircuit also places a calling condition upon the multiplecommutator segments 111 of the group of lines to which substation Abelongs. Relay 114, in attracting itsarmature, closes the followingcircuit for a relay115: free pole of battery, armature and front contactof relay114:,conductor 116, finder side-switch arm 1 and its firstcontact, conductor 117, left winding of relay 115, conductor 118 toground at themmature and back contact of the primary stepping magnet 119ofthe finder. Relay 115,

in attracting its armature, closes the circuit of magnet 119, and themagnet 119, in attracting its armature, opens thecircuit of relay 115.Thus the finder brush shaft 120 is given a primary movement in search ofthe calling group. "l/Vhen the brush 121, which rotates with the brushshaft 120, encounters multiple segment-111 of the calling group, nowgrounded, the following circuit of the finder side switch: free pole ofbattery, resistance 112, right armature and front contact of relay 100,conductor 113,

segments 111, brush 121, conductorl23,arm

0 and its first contact, magnet-122, conduc ranged torclose the circuitfor magnet 1'22 and the right winding of relay 115," beforethe'circuitthrough the leftwinding of "relay is broken by thearmatureof-magnet 119. 'R'ela-y 115 is adaptedto 'energize in thiscircuit, with the result that magnet 119 is maintained energized for aninstant after the last step to prevent the shaft 120 from overthrowing.The escape magnet 122 is constructed to release the side switch fromposition to position upon its energization, and upon the closure of thecircuit traced, releases the side switch into position 2. Arm 6, inmoving off its first contact, deenergizes escape magnet 122 and relay115. In position 2, arm 6 shunts out relay 114, with the result that thein-starter 132 is connected to the out-starter wire 131 over arm 1 andits second contact. A call may now come in from another group over theiii-starter wire 132, and set the finder connected to the out-starterwire 131 in motion, while the finder shown in the drawing is making itssecondarv movement in search of the calling line. Upon the terminationof the primary movement of the finder and the release of the side switchinto its second position, arm 5 closed the following circuit for thesecondary stepping magnet 133 of the finder, to drive the positionedbrushes 125, 126, 127 over the multiples of the calling group containingthose of the Calling line: free pole of battery, magnet 133, itsarmature and back contact, arm 5 and its second contact to ground. Inposition 2 of the side switch, arm 4 connects the escape magnet 122 totest brush 127. hen the test brush 127 reaches the test multiples 110 ofthe calling line, upon which a calling condition has been placed by theattraction of the left armature of relay 100, escape magnet 122 becomesenergized and releases the side switch into position 3. Although theright winding of relay 115 is included in the circuit of magnet 122 asbefore, it is not adapted to respond, through the resistance 108.

Arm 5. in leaving its second contact, opens the circuit of the secondarystepping magnet 133. thus stopping the finder brushes 125, 126, 127 uponthe multiples of the calling line 128, 129, 110. The escape magnet 122will not energize as brush 127 passes over multiples 110 of non-callinglines, since it will not receive enough current. In position 3, arm 1maintains the continuity of the in and out-starter wires 132, 131. Arm4, in moving into position 3, closes the following circuit to energizethe cut-off relay 1020f the calling line: free pole of battery, relay102, conductor 134. conductor 135, test multiples 110, test brush 127,conductor 136, arm 4 and its third contact to ground. Relay 102, inattracting its armatures, deenergizes the line relay 100, which, inretracting its left armature, removes the calling condition from themultiples 110 of the calling line in the finders in which it appears,and in retracting its right armature, removes the calling condition fromthe multiple commutator segments 111 of the calling group. Arms 2 and 3,in moving into position 3, energize a relay 137 over the followingcircuit: free pole of battery, left winding of relay 137, conductor 138,talking conductor 139, arm 2 and its third contact, conductor 140, brush125, terminal 128, conductor 104, telephonic apparatus at substation A,conductor 105, terminal 129, brush 126, arm 3 and its third contact,conductors 141, 136, right winding of relay 137 to ground. Relay 137energizes and interposes a break in the circuit of the finder releasemagnet 143 before the side-switch arm 5 is closed sufiiciently long topermit the energization of such release magnet. Relay 137, by attractingit armature, energizes a slow relay 144 over sideswitch arm 5 and itsthird contact. Relay 144, in attracting its armature, interposes anotherbreak in the circuit of release magnet 143. The relay 137 may be thestepping relay of the first selector, or in the case of a system wherethe line finders merely distribute calls to idle operators, may operatea calling lamp, whereupon the operator may complete the connection inany suitable manner.

Going back to that point in the operation where the escape magnet 122released the side switch into position 2, when brush 121 reachedgrounded calling group segments 111, arm 6, in moving into position 2,shunts out relay 114, which, in retracting its armature, connectsin-starter wire 132 to conductor 116, which conductor is connected overarm 1 in this position, through slow relay 146 to out-starter wire 131,and from thence to relay 115 of the next idle finder. If, when relay 114retracts its armature, the ;in-starter wire 132 is connected to freepole of battery, a circuit is closed to start the next idle finder withwhich the out-starter wire 131 is associated in search of the line whosecall caused such connection to battery of conductor 132. The circuit maybe traced as follows, assuming the finder shown to belong to the groupinitiating such call: free pole of battery, armature and front contactof relay 114, conductor 116. arml and its third contact, slow relay 146,outstarter wire 131, in-starter wire 132 of the finder shown, armatureand back contact of relay 114, conductor 116, arm 1 and its secondcontact, slow relay 146, out-starter wire 131, in-starter wire 132 ofthe idle finder, armature and back contact of relay 114, conductor 116,arm 1 and its first contact, conductor 117, left winding of relay 115,conductor 118, armature and back contact of the primary magnet 119 ofsuch finder to ground. The magnet 119 and relay 115 of such finder willnow interact to finder will energize and release the side switch intoposition 2, in which position the secondary movement of the shaft willtake place to drive the positioned brushes over the multiples of thecalling group, as already described.

The brush 121 is keyed to the shaft 120 as shown to rotate therewith.However, such brush does not partake of the vertical movement of theshaft, but remains in contact with the calling group commutator segments111. This is necessary in order to maintain relay 114 shunted out;otherwise this relay would reenergize upon the first secondary step, anddisconnect the in-starter wire 132 from conductor 116 leading to theoutstarter wire 131.

A slow relay 146 is provided for each finder. The function of theserelays is to interpose a break in the circuit of the release magnets ofthe finders with which they are associated, while a finder beyond isoperating over a circuit passing through sideswitch arms 1 and the thirdcontacts of such finders, since if one of these intermediate findersreleases during the operation of the finder being set, the side-switcharm 1 of such released finder will, in moving back to its first contact,upon the energization of the associated release magnet, disrupt thestepping circuit.

What is claimed is:

1. In a telephone exchange system, the combination with telephone lines,automatic line finder switche to which said lines are multipled ingroups, a starter wire for associating an idle finder with said lines,means adapted upon the initiation of a call to give said finder aprimary movement to place the same in operative relation to multiples ofthe calling group, and means for automatically giving said finder asecondary movement to connect with the calling line multiples, of meansactuated upon the termination of the primary movement to extend thestarter wire to the next idle finder.

2. In a telephone exchange system, the combination with telephone lines,automatic line finder switches to which said lines are multipled ingroups, stepping magnets for giving said finders a primary and secondarymovement, a starter wire for associating an idle finder with said lines,means adapted upon the initiation of a call to operate said primarystepping magnet over said starter wire, and means for operating saidsecondary stepping magnet automatically upon the termination of saidprimary movement to Copies of this patent may be obtained for cause saidfinder to connect with the calling line, of means actuated upon thetermination of the primary movement for extending the starter wire tothe next idle finder.

3. In a telephone exchange system, the combination with telephone lines,automatic finder switches to which said lines are mul-i tipled ingroups, primary and secondary stepping magnets for said finders, astarter wire for associating an idle finder with said lines, and a linerelay adapted upon the initiation of a call to place a calling conditionupon the test multiples of the calling line in such finders and upon themultiple group segments of the calling group in such finders, of astarting relay energized upon the operation of said line relay tointerpose a break in the incoming end of said starter wire and tooperate said primary stepping magnet over a portion of said starterwire, and a brush carried by said finder adapted when the calling groupsegment is reached to stop the operation of said primary magnet and todeenergize said starting relay to reconnect the incoming end of saidstarter wire to the outgoing end thereof.

4. In a telephone exchange system, the combination with telephone lines,automatic line finder switches to which said lines are multipled ingroups, side switches for controlling said finders, escape magnetstherefor, primary and secondary stepping magnets for said finders, arelay 114, a starter wire for associating an idle finder with said linesover a back contact of relay 114 and an arm of the associated sideswitch, a line relay adapted upon the initiation of a call to place acalling condition upon the multiples of the line in the finders in whichit appears and on the calling group segments in such finder and toenergize relay 114 to interpose a break in the incoming end of saidstarter wire and to operate said primary stepping magnet over a portionof said starter wire, of a brush carried by said finder adapted when themultiple calling segment is reached to shunt out said relay 114 andoperate the escape magnet 122 of said side switch which releases theside switch into position 2 to close the circuit of said secondarystepping magnet, said relay 114 at its back contact reconnecting theincoming section of the starter wire through said side-switch arm andits second contact to the out-starter wire.

In witness whereof, I hereunto subscribe my name this th day of April A.D., 1916.

ALBEN E. LUNDELL.

five cents each, by addressing the Commissioner of'Patents, Washington,D. G.

